The Surface Coating of YAG:Ce Phosphors with ZnO Nanoparticles for White LED

Abstract

In this work, YAG: Ce phosphors coated with ZnO nanoparticles were prepared based on the wet chemical method in ethanol solution at low temperature. The surface character was characterized by XPS and SEM. The XPS spectra showed that the peak positions corresponding to the Zn 2p3/2 , Zn 2p1/2 and O 1s are 1022.08 eV, 1044.88 eV and 530. 8 eV, respectively. The SEM images showed that the surface of YAG:Ce were coated with ZnO nanoparticles. The thickness is about 25 nm. The luminescence properties of YAG:Ce phosphors coated with ZnO nanoparticles were studied. It is found that the photoluminescence intensity of coated phoshors increases a maximum at 12% compared with that of the uncoaed YAG: Ce phosphors and the enhancement of photoluminescence intensity depends on the consistency of ZnO nanoparticles. Finally, the YAG: Ce phosphors coated with ZnO nanoparticles were used for LED package. The results show that the luminescent intensity increases 6.8 % and the quantity of phosphors decreases 1 %. It is important for the lighting product to improve the luminescence intensity of white LED and decrease the cost of package.